Eogammarus Birstein, 1933

Tomikawa, Ko, Morino, Hiroshi, Toft, Jason & Mawatari, Shunsuke F., 2006, A revision of Eogammarus Birstein, 1933 (Crustacea, Amphipoda, Anisogammaridae), with a description of a new species, Journal of Natural History (J. Nat. Hist.) 40 (17 - 18), pp. 1083-1148 : 1084

Genus Eogammarus Birstein, 1933

Eogammarus Birstein 1933, p 149 ; Bousfield 1979, p 312 –321.

Type species. Gammarus kygi Derzhavin 1923, p 185 –187, Plate I.

Diagnosis

Eye present, reniform. Antenna 1 longer than half of body; peduncles setose; accessory flagellum four- to eight-articulate, each article with one or two aesthetascs. Antenna 2 slightly shorter than antenna 1; flagellum with calceoli in male and often in female. Pereonites smooth. Pleonites smooth or carinate; dorsal margin with four fine setae (rarely more). Dorsal margin of urosomites 1 and 3 with pair of lateral clusters of robust setae and pair of medial clusters of robust setae, with interspersed fine setae; urosomite 2 with pair of lateral clusters of robust setae, with interspersed fine setae. Upper lip convex, with minute setae. Left and right incisors of mandible five- and four-dentate, respectively; left lacinia mobilis four-dentate, right lacinia mobilis two-edged. Inner lobe of lower lip incompletely fused. Outer plate of maxilla 1 with 11 serrated robust setae apically. Inner plate of maxilliped reaching distal end of palp article 1; palp article 2 weakly expanded, inner margin with numerous setae, ventral face with clusters of setae; palp article 3 expanded distally, with clusters of setae on dorsal and ventral margins; palp article 4 tipped with long nail and a few setae. Coxal gills on pereopods 2–7; accessory lobes double on gills of pereopod 2–5, treble on 6, single on 7. Brood plates pear-shaped on pereopods 2–5; fringed with numerous setae. Pleopods powerful; retinacula on peduncles paired or triplicated; inner basal margin of inner ramus with clothespin setae. Inner ramus of uropod 3 short; outer ramus long, margins with clusters of robust setae and several plumose and simple setae, terminal article distinct, with distal setae. Telson cleft, lobes with robust apical and distolateral setae (rarely lacking).